The Age-Related Eye Disease Study is a multicenter prospective cohort study of the clinical course, prognosis and risk factors for age-related macular degeneration and cataract. An important goal of AREDS was the de­velopment of a se­verity scale for AMD, to pro­vide baseline risk categories, to allow tracking of progression, and to define sur­rogate outcomes for progression to ad­vanced AMD. The scale uses neovascular AMD and geographic atrophy involving the center of the mac­ula as the principal outcome measures.

The AREDS Re­search Group developed the nine-step severity scale, which combines a six-step drusen area scale with a five-step pigmentary ab­normality scale. On it, the five-year risk of ad­vanced AMD increased progressively from less than 1 percent in step one to about 50 percent in step nine. Among the 334 eyes that had at least a three-step progression on the scale between the baseline and five-year visits, almost half showed stepwise progression through intervening severity levels at intervening visits. Replicate gradings showed agreement within one step on the scale in 87 percent of eyes.

The scale provides convenient risk categories and has acceptable reproducibility, the re­search­ers conclude. Progression along the scale may prove to be useful as a surrogate for pro­gression to advanced AMD. In AREDS, stereo color fundus photographs were taken at baseline, at two  years and annually thereafter. Photographs were graded for drusen characteristics, pigmentary ab­normalities, and presence of abnormalities characteristic of neo­vascular AMD. Advanced AMD was defined as presence of one or more neovascular AMD ab­nor­malities, photocoagulation for AMD, or geographic atrophy involving the center of the macula. The researchers explored associations among right eyes of 3,212 participants between severity of drusen characteristics and pig­mentary abnormalities at baseline and development of advanced AMD within five years of follow-up.

(Arch Ophthalmol 2005;123:1484-1498.)

Age-Related Eye Disease Study Research Group. AREDS Report No. 17.

 

Artificial Tears Offer Temporary Improvement in Visual Acuity

A common preservative-free artificial tear, carboxymethylcellulose (CMC) 0.5% provides temporary but significant visual acuity improvement in symptomatic and asymp­tomatic dry-eye patients, according to a non­­randomized, prospective trial in New York City.

Twenty symptomatic dry-eye patients (40 eyes) and an equal number of asymptomatic dry-eye patients, all 40 years and older, were recruited. Dis­tance VA was measured by ETDRS chart and near visual acuity was measured by the Light­house Near Vision chart before and 30 seconds after instillation of one drop of CMC (Refresh Plus, Allergan). Acuity was measured with and with­out correction. The duration of action of CMC was measured at one-minute intervals until the patient's VA re­turned to pretear level.

In both groups, uncorrected and corrected near and distance vision showed a statistically significant improvement after CMC (p<.05). There was no significant difference in improvement be­tween the two groups in all categories (p>.05). The mean duration of improvement of vision was 2.93 minutes in the symptomatic group and 3.70 minutes in the asymptomatic group (p=.036).

The effect of artificial tears on VA may be of diagnostic value in detecting ocular surface abnormality in symptomatic and asymptomatic patients, the researchers report. 

(AJO 2005;140:830-835.)

Nilforoushan M, MDab, Latkany R, Speaker M.